Acid esters of polyoxypropylated propylene diamines



Patented May 25, 1954 UNITED STATES PATENT OFFICE ACID ESTERS F POLYOXYPROPYLAT-ED PROPYLENE DIAMINES Melvin De Groote, University City, Mo., assignor to Petrolite Corporation, a corporation of Delaware No Drawing. Application May 14, 1951, Serial No. 226,313

Claims. (Cl. 260475) The present invention is a continuation-in- More specifically, the present invention is .conpart of my copending applications, Serial Nos. cerned with a fractional ester obtained from a 104,801 filed July 14, 1949 (now Patent 2,552,528, polycarboxy acid and a compound derived in turn granted May 15, 1951), 109, 619 filed August 1-0, by the oxypropylation of propylenediamine .or an 1949 (now Patent 2,552,531, granted May 15, 5 equivalentdiamine as hereinafter specified, hav- 1951), and 107,381 filed July 28, 1949 (now ing four terminal hydroxyl radicals or the Patent 2,552,530, granted May .15, 195.1). equivalent, 1 e, labile hydrogen atoms ep- The pres nt invention is con elned with certible to oxyalkylation Indeed as pointed out tain new chemical products, compounds, 01 comhereinafter the diam ne derivative need only have positions which have useful application in var- .a plurality of reactive hydrogen atoms, i. e., 2 ions arts. It includes methods or procedures or more. for manufacturing said new chemical products, The most suitable raw material is propylenecompounds or compositions, as well as the proddiamine as such or after treatment with several ucts, compounds, or compositions themselves. moles of ethylene oxide or glycideor a combina- Complementary to the above aspect of the intion of the two, and particularly propylenevention herein disclosed is my companion invendiamine after being treated with one to four or tion concerned with the use of these particular even five or six moles of ethylene oxide. The chemical compounds, or products, as demulsifyinitial diamino compound must be characterized ing agents in processes or procedures particuby (a) .having 2 amino nitrogen atoms and preflarly adapted for preventing, breaking, or reerably both being basic; (2)) .free from any radsolving emulsions of the water-in-oil type, and ical having 8 or more carbon atoms in an uninparticularly petroleum emulsions. See my 00- terrupted group; (a) must be water-soluble; and pending application, Serial No. 226,312, filed May (d) have a plurality of reactive hydrogen atoms, 14, 1951, now Patent No. 2,626,919. preferably at least 3 or 4.

Said last aforementioned co-pending applica- Needless to say, the most readily available tion, 1'. e., Serial No. 107,381, describes high molal reactant. to wit, propylenediamine, has 4 reactive oxypropylation derivatives of monomeric polyhydrogen atoms and this would still be true amine compounds with the proviso that (a) the after reaction with ethylene oxide, for instance, initial polyamino reactant .be free from any rad- 1 to 4 moles of ethylene oxide. However, reical having at least 8 uninterrupted carbon action Withglycide would provide as many as 8 atoms; (2)) the initial poly-amino reactant have a reactive hydrogen atoms provided that the molal molecular weight of not over 1800 and at least a ratio was 4 to l, i. e., 4 moles of glycide for one plurality of reactive hydrogen atoms; (0) the mole of diamine. On the other hand, if proinitial polyamino reactant must be water-soluble; pylene .diamine were treated with a mole of an (d) the oxypropylation end product must be .alkylating agent .so as to introduce an alkyl radwater-insoluble; (e) the oxypropy-lation end ical such as methyl, ethyl, propyl, butyl, hexyl, product be within the molecular weight range of heptyl, or the like, or an aryl radical such as a 2,000 to 30,000 on an average statistical basis; phenyl radical, then and in that event the numpylation end product in respect to water must be creased to as few as two and still be acceptable step; (-0) the ratio of propylene oxide per initial allcyclic radical, such as a cyclohexyl radical, or reactive hydrogen atom must be within the range an alkylaryl radical such as benzyl radical, were of 7 to '70; (h) the initial polyamino reactant introduced the basicity of the nitrogen atom must represent not more than 20% by weight of would not be materially efi'ected. However, the the oxypropylation end product -on a statistical introduction of a phenyl radical would, of course, basis; (2') the preceding provisos are based on the markedlyaffect.thebasicity of the nitrogen atom. assumption of complete reaction involving the For obvious reasons my choice is as follows:

propylene oxide and initial polyamino reactant; (a) The use of propylenediamine rather than (7) the polyamino reactant must contain at least any substituted propylenediamine .as described; one basis nitrogen atom; and (7c) the nitrogen (b) The use of propylenediamine after treatatoms are linked by a carbon .atom chain. ment with l to 5 moles of ethylene oxide although Furthermore, in said aforementioned co-penda modestly increased amount of ethylene oxide ing application it was pointed out that such hycan be used in light of what is said hereinafter; droxylated materials obtained by oxypropyla'tion or could be reacted with dicarboxy acids such as (c) The use of a derivative obtained from prodiglycollic acid to yield valuable derivatives pylenediamine after reaction with glycide, or a which are satisfactory also for demulsiflcation mixture of ethylene oxide and glycide. of petroleum emulsions. Since reaction of propylenediamine with Thepresent invention is concerned with a fracpropylene oxide is invariably involved and since ticnal ester obtained from a polycarboxy acid this oxyalkylation step is substantially the same and a polyhydroxylated material obtained by the as the use of ethylene oxide or glycide for puroxypropylation of a polyamino reactant. pose of brevity further reference simply will be made to propylenediamine as illustrating the procedure, regardless of selected. It is not necessary to point out, of course, that the substituted propylenediamines, i. e., those where an alkyl, alicyclic, aryl-alkyl, or aryl group has been introduced can similarly be subjected to reaction with ethylene oxide, glycide, or a combination of the two.

I also went to point out it is immaterial whether the initial oxypropylation step involves hydrogen attached to oxygen or hydrogen attached to nitrogen. The essential requirement is that it be a labile or reactive hydrogen atom. Any substituent radical present must, of course, have less than 8 uninterrupted carbon atoms in a single group.

More specifical1y, then, the present invention is concerned with hydrophile synthetic products; said hydrophile synthetic products being the acidic fractional esters derived by reaction between (A) a polycarboxy acid and (B) high molal oxypropylation derivatives of monomeric diamino compounds, with the proviso that (a) the initial diamino reactant be free from any radical having at least 8 uninterrupted carbon atoms; (19) the initial diamino reactant have a molecular weight of not over 800 and at least a plurality of reactive hydrogen atoms; the initial diamino reactant must be water-soluble; (d) the oxypropylation end product must be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2000 to 30,000 on an average statistical basis; (I) the solubility characteristics of the oxypropylation end product in respect to water and kerosene must be substantially the result of the oxypropylation step; (g) the ratio of propylene oxide per initial reactive hydrogen atom must be within the range of '7 to 70; (h) the initial diamino reactant must represent not more than 20% by weight of the oxypropylation end product on a statistical basis; (i) the preceding provisos are based on the assumption of complete reaction involving the propylene oxide and initial diamino reactant; (7') the nitrogen atoms are linked by a propylene chain, and with the further proviso that the ratio of (A) to (B) be one mole of (A) for each hydroxyl radical present in (B).

What has been said previously the materials herein described and particularly for use as demulsifiers with reference to frac,

tional esters may be and probably is an oversimplification for reasons which are obvious on further examination. It is pointed out subsequently that prior to esterification the alkaline catalyst can be removed by addition of hydrochloric acid. Actually the amount of hydrochloric acid added is usually suflicient and one can deliberately employ enough acid, not only to neutralize the alkaline catalyst, but also to neutralize the amino nitrogen atom or convert it into a salt. Stated another way, a trivalent nitrogen atom is converted into a pentavalent nitrogen atom, i. e., a change involving an electrovalency indicated as follows:

X wherein I-IX represents any strong acid or fairly strong acid such as hydrochloric acid, nitric acid, sulfuric acid, a sulphonic acid, etc., in which what particular reactant is,

in regard to represents the acidic hydrogen atom and X represents the anion. Without attempting to complicate the subsequent description further it is obvious then that one might have esters or one might convert the esters into ester salts as described. Likewise another possibility is that under certain conditions one could obtain amides. The explanation of this latter fact resides in this observation. In the case of an amide, such as acetamide, there is always a question as to whether or not oxypropylation involves both amido nitrogen atoms so as to obtain a hundred per cent yield of the dihydroxylated compound. There is some evidence to at least some degree that a monohydroxylated compound is obtained under some circumstances with one amido hydrogen atom remaining without change.

Another explanation which has sometimes appeared in the oxypropylation of nitrogen-containing compounds particularly such as acetamide, is that the molecule appears to decompose under conditions of analysis and unsaturation simultaneously. One suggesthat one hydroxyl is lost by dehydration a break in the molecule in such a way that two new hydroxyls are formed. This is shown after a fashion in a highly idealized manner in the following In the above formulas the large X is obviously not intended to signify anything except the central part of a large molecule, whereas, as far as a speculative explanation is concerned, one terminal radicals, as shown. Such suggestions is of interest only because it may be a possible explanation of how an increase in hydroxyl Value does take place which could be interpreted as a decrease in molecular weight. This matter is considered subsequently in the final paragraphs of Part 2. This same situation seems to apply in the oxypropylation of at least some polyalkylene amines and thus is of significance in the instant situation.

In the case of higher polya-mines there is evithe available hydrogen atoms are not necessarily attacked, at least under comparatively modest oxypropylation conditions, particularly when oxypropyla-tion proceeds at low temperature as herein described, for instance, about the boiling point of water. For instance, in the case of diethylene triamine there is some evidence that one terminal hydrogen atom only in each of the two end groups is first attacked by propylene oxide and then the hydrogen atom attached to the central nitrogen atom is attacked. It is quite possible that three long propylene 0xide chains are built up before the two remaining hydrogens are attacked and perhaps not attacked at all. This, of course, depends on the conditions of oxypropylation. However, analytical procedure is not entirely satisfactory in some instances in differentiating between a reactive hydrogen atom attached to nitrogen and areactive hydrogen atom attached to oxygen.

In the case of triethylenetetramine the same situation seems to follow. One hydrogen atom on the two terminal groups is first attackedand then the two hydrogen atoms on the two intermediate nitrogen atoms. Thus four chains tend to build up and perhaps finally, if at all, the remaining two hydrogen atoms attached to-the'two terminal groups are attacked. In the case of tetraethylenepentamine the same approachseems described compounds are concerned it would be absolutely immaterial exsions of the water-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being a cogeneric mixture selected from the class consisting of acidic fractional esters, acidic ester salts, and acidic amido derivatives obtained by having at least 8 uninterrupted (b) the initial diamino reactant having a molecular weight of not over 800 and soluble; (d) the oxypropylation end product'must "be water-insoluble, and kerosene-soluble; (e) the oxypropylation end product be within the molecular weight range of 2,000 to 30,000 on an average statistical basis; (f), the solubility characteristics of the oxypropylation end product in respect to water and kerosene must be substan- 'tially the result of the oxypropylation step;

(A) a polycarboxy acid, and

chain, and with the final proviso that the ratio of (A) to (B) be one mole of 4 A) for each 'hydroxyl radical present in (B).

Although the herein described products have a number of industrial applications, they are of particular value for resolving petroleum emulsions of the wa-ter-in-oil type that are -common ly referred to as cut oil, 'roily oil, emulsified oil, -etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in'a more or less permanent state throughout the oil which constitutes the continuous phaseof the emulsion. This specific application is described and claimed inmy co-pending application, Serial No. 226,312, filed May 14, 1 951.

The new products are useful as wetting, detergent and leveling agents in the laundry, textile and dyeing industries; as wetting agents and detergents in the acid washing of building stone and brick; as wetting agents and spreaders in the application of asphalt in road building and the like; as a flotation reagent in the flotation separation of various aqueous suspensions containing negatively charged particles such as sewage, coal washing waste water, and various trade wastes and the like; as germ'ic'ides, insecticides, emulsifying agents, as for example, for cosmetics, spray oils, water-repellent textile finishes; as lubricants, etc.

For convenience, what is said hereinafter will be divided into four'parts:

Part 1 is concerned with the preparation of the oxypropylation derivatives of propylenediamine or equivalent initial reactants;

Part 2 is concerned with the preparation of the esters from the oxypropylatedderivatives;

Part 3 is concerned with 'the natureo'f the oxypropylation derivatives insofar that a cogeneric mixture is invariably obtained; and

Part 4 is concerned with "the use of certain valuable derivatives which can :be obtained readily from the herein described fractional esters.

PART 1 For a number of well known reasons equipment, whether laboratory :size, semi-pilot plant size, *pilot plant size, or large scale size, is not as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, or particularly in the case of laboratory equipment and pilot plant size the design :is such as to use any of thecustomarily available alkylene oxides, i. e., ethylene oxide, propylene oxide, butylene oxide, glycide, epichlorohydrin, styrene oxide, etc. In

the subsequent description of the equipment it becomes obvious that it is adapted for ox-yeth- -ylation as *well as .oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, .not only in regard to *pres ence orabsence of'catalystgand thekind of catato (h') the initial diamino reactant must repby weight of the oxylyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures :up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They :can be conducted also at temperatures approximating the boiling point of water or slightlyabove, as for example to 0. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedure is employed as is some- -inert gas such as nitrogen in the vessel during the reaction. Such 'low-temnerature-low reac- .tion rate oxypropylations have been described very completely in U. S. Patent No. 2,448,664 to H. R. Fife et al., dated September '7, 1948. Low temperature, low pressure oxypropylations are particularly desirable where the compound being subjected to oxypropylation contains one, two or three points of reaction only, such as monohydric alcohols, glycols and triols.

The initial reactants in the instant application contain at least 2 reactive hydrogens and for this reason there is possibly less advantage in using low temperature oxypropylation rather than high temperature oxypropylation. However, the reactions do not go too slowly and this particular procedure was used in the subsequent examples.

Since low pressure-low temperature-low-reaction-speed oxypropylations require considerable time, for instance, 1 to '7 days of 24 hours each to complete the reaction they are conducted as a rule whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with two added automatic features; (a) a solenoid controlled valve which shuts 01f the propylene oxide in event that the temperature gets outside a predetermined and set range, for instance, 95 to 120 C., and (b) another solenoid valve which shuts on the propylene oxide (or for that matter ethylene oxide if it is being used) if the pressure gets beyond a predetermined range, such as 25 to pounds. Otherwise, the equipment is substantially the same as is commonly employed for this purpose where the pressure of reaction is higher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylation whether it he oxypropylation or oxyethylation. With certain obvious changes the equipment can be used also to permit oxyalkylation involving the use of glyc ide where no pressure is involved except the vapor pressure of a solvent, if any, which may have been used as a diluent.

As previously pointed out the method of using propylene oxide is the same as ethylene oxide. This point is emphasized only for the reason that the apparatus is so designed and constructed as to use either oxide.

The oxypropylation procedure employed in the preparation of the oxyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous automatically-controlled procedure was employed. In this procedure the autoclave was a conventional autoclave made of stainless steel and having a capacity of approximately 15 gallons and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the variable-speed stirrer operating at speeds from 50' R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, 'such as propylene oxide or ethylene oxide,

to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave; such as a cooling jacket, and, preferably, coils in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autoclaves are, or course, in essence small-scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations an autoclave having a smaller capacity, for instance, approximately 3 /2 liters in one case and about 1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, was achieved by the use of a separate container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about pounds was used in connection with the 15-gallon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight feed glass, thermometer, connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing so that continuous weighings could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls which shut off the propylene oxide in event temperature of reaction passes out of the predetermined range or if pressure in the autoclave passes out of predetermined range.

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few degrees of any selected point, for instance, if C. was selected as the operating temperature the maximum point would be at the most C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure was held at approximately 30 pounds maximum within a 5-pound variation one way or the other, but might drop to practically zero, especially where no solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days ('72 hours), for completion of the final member of a series. In some instances the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned. The minimum time recorded was about a 6-hour period in a single step. Reactions indicated as being complete in 7 or 8 hours may have been complete in a lesser period of time in light of the automatic equipa 8-hour period there. would be an unquestionable speeding up of the reaction, by Simply repeating the example and. using 4, or 6 hours instead of 8. hours.

When operating at a compartively high. tempera-ture, for instance, between 150 to 200 0., an unreacted alkylene oxide such as pr pyl n oxide; makes its presence felt in the increase in happen that the propylene oxide goes in as: a liquid. If so, and if it remains unreacted. there.

possibility;v if need he a. sample must be with-- drawn and examined for unreacted propylene 0X- ide. One ObVlOLlS procedure, of course, is to oxya modestly higher temperature, 011 to 150 C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound. obtained.v The higher the molecular weight of the compound, i. e., towards the tion, the longer the time required to add a given amount of oxide- One possible explanation is that the molecule, bein larger, the opportunity for randor reaction is decreased. Inversely, the lower. the molecular weight the faster thev reaction takes place. For this reason. sometimes; at

ously, operating at a low pressure and. a low temperature even in large scale operations" as much. as aweek or ten days time: may elapseto obtain some of the higher molecular weight derivatives. from monohydric or dihydric' materials.

In' a number of operations the. counterbalance scale or dial scale so as to raise or lower the temperature.

run which was-shut off incase the pressure passed.

the points of design, construction, etc., were con.- ventional. including the gauges, checkvalvesand? entire equipment. As far as-I am awareat least twofirms, and possibly three, specialize in autoclave equipment such as- I have employed. in the laboratory, and are prepared. to furnish equipment of this same kind. similarly pilot plant equipment is available. This point issimply made asa.v precaution in the direction. of safety. Oxyalkylations, particularly involving ethylene oxide, glycide, propylene oxide, etc., should not be conducted except in equipment specially designed for the purpose.

It is to be noted in the present instance one may or'may' not havebasic nitrogen atoms present. For example, if'a phenyl radical is attached to each nitrogen atom the initial diamine' is substantially nonbasic. However; if one'employs propylenediamin'e' there are present two basic nitrogen atoms and thus the addition of an alkalinecatalyst can be eliminatedin the early stages of' oxypropylation or oxyethylation. This is illustrated subsequently by the fact that oxypropylation was permitted to go through the first stage without the addition of alkaline catalyst.

Example In The particular autoclave employed was one with. a capacity of about 15 gallons: or on. the average of about pounds of reaction mass; The. speed of the stirrer could be varied from to 350 R. P. M. The initial charge was 7.25 pounds of. propylenediami-ne. In the initial charge .75 poundof caustic. soda was added notwithstanding the fact that the first oxypropylationwould have taken place satisfactorily without any added: alkalinity. The reaction pot was flushed out with nitrogen, the: autoclave sealed, and the automatic devices. set for. injecting. 87.5. pounds of propylene oxide in- 13 hours. The oxide was injected at. about the rate of 6 or 7 pounds per hour. The pressure regulator was set for a maximum pressure of 35-37 pounds per square inch; However, in this step andin all. succeeding :stepscthe pressure never got over 33.5 pounds. per square: inch- In fact, this. meant that the: bulk of the reaction could take place and did'. take place at an. appreciably lower pressure. Thiscomparatively low pressure was the. result of. the fact that. the reactant. per se was basic and. a. fair amount of catalyst had fi l-.5: pounds ofreaction mass identified as EX- ample 1a, preceding, and. equivalent to 3.90 pounds; of diamine;, 47.20 pounds of propylene oxide, and .4. pound. of caustic soda, were permitted to remain in the reaction vessel- No further catalyst was added. The mixture was then reacted with 43.75 pounds of propylene oxide. The oxypropyl'ation was conducted: in

11 substantially the same manner as in regardto temperature and pressure as in Example 1a, preceding. The time period, however, was considerably shorter insofar that much less oxide was added. The addition was made at about the rate of 11 or 12 pounds per hour. The oxypropylation was conducted in substantially the same manner as far as temperature and pressure were concerned as in Example 1a, preceding. At the end of the reaction period part of the reaction mass was withdrawn and oxypropylation continued as described in Example 3a., following.

Example 311 52.25 pounds of the reaction mass identified as Example 2a, preceding, and equivalent to 2.14 pounds of the diamine, 49.89 pounds of propylene oxide, and .22 pound of caustic soda, were permitted to remain in the autoclave. 36 pounds of propylene oxide were introduced during a 6-hour period. No additional catalyst was added. The conditions of reaction as far as temperature and pressure were concerned were susbtantially the same as in Example la, preceding. At the completion of the reaction part of the reaction mass was withdrawn and the remainder subiected to further oxypropylation as described in Example 4a, following.

Example 4a Example 5a 7 49.13 pounds of reaction mass identified as Example 4a, preceding, were permitted to remain in the autoclave. No additional catalyst was added. 17 pounds of propylene oxide were introduced in an 8-hour period. The rate was approximately 2 pounds per hour. The conditions of temperature and pressure were substantially the same as in Example 1a, preceding. This particular oxypropylation series was stopped at this point.

What has been said herein is presented in tabular form in Table I immediately following with some added information as to molecular weight and as to solubility of the reaction prod- 5 in water, soluble in xylene was emulsifiable in water, soluble in xylene, but insoluble in kerosene; Example 3a. was insoluble in water, soluble in xylene, and insoluble in kerosene; Examples 4a and 5a were both insoluble and soluble in kerosene.

The final product, i. e., at the end of the oxypropylation step, was apt to be either a straw color, or sometimes it would have a more definite reddish-amber or a distinct dark-amber tinge. In the later stages the product was invariably water-insoluble and kerosene-soluble. This is characteristic of all the products obtained from the diamino products herein described. Needless to say if more ethylene oxide radicals were introduced into the initial raw material the initial product is more water-soluble and one must go to higher molecular weights to produce waterinsolubility and kerosene-solubility, for instance, molecular weights such as 10,000 to 12,000 or more on a theoretical basis, and 5000 to 6000, or even more, on a hydroxyl molecular weight basis. If, however, the initial diamino compound is treated with one or more or perhaps several moles of butylene oxide then the reverse effect is obtained and it takes less propylene oxide to produce water-insolubility and kerosene-solubility. These products were, of course, alkaline due in part to the residual caustic soda employed. This would also be the case if sodium methylate were used as a catalyst.

Speaking of insolubility in water or solubility in kerosene such solubility test can be made simply by shaking small amounts of the materials in a test tube with water, for instance, using 1% to 5 aproximately based on the amount of water present.

Needless to say, there is no complete conversion of propylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular weight based on a statistical average is greater than the molecular weight calculated by usual methods on basis of acetyl or hydroxyl value. Actually, there is no completely satisfactory method for determining molecular weights of these types of compounds with a high degree of accuracy when the molecular weights exceed 2,000. In some instances the acetyl value or hydroxyl value serves as satisfactorily as an index to the molecular weight as any other procedure, subject to the above limitations, and especially in the higher molecular weight range. If any difiiculty is encountered in the manufacture of the esters as described in Part 2 the stoichiometrical amount of acid or acid compound should be taken which corresponds to the indicated acetyl or hydroxyl value. This matter has been discussed in the literature and is a matter of common knowledge and requires no a uct 1n water, xylene, and kerosene. 0 further elaborat1on. In fact, it 1s illustrated by TABLE I 3 Composition Before Composition at End M Max E N by Max. Pres Time Amine Oxide Oata- Theo. Amine Oxide Cataggz s h Hrs. Amt, Amt, lyst, M01. Amt., Amt., st,

lbs lbs lbs. Wt. lbs. lbs. lbs. m 5

Example 1a was soluble in water, soluble in xylene, but insoluble in kerosene; Example 2a 5 some ofthe examples appearing in the patent previously mentioned.

13 PART 2- As previously pointed out the present invention is concerned with acidic esters obtained from the oxypropylated derivatives described in Part 1, immediately preceding, and polycarboxy acids, particularly tricarboxy acids like citric and dicarboxy acids such as adipic acid, phthalic acid, or anhydride, succinic acid, diglycollic acid, sebacic acid, azelaic acid, aconitic acid, maleic acid or anhydride, citraconic acid or anhydride, maleic acid or anhydride adducts as obtained by the Diels-Alder reaction from products such as maleic anhydride, and cyclopentadiene. Such acids should be heat stable so they are not decomposed during esterification. They may contain as many as 36 carbon atoms as, for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarboxy fatty acids, or unsaturated monocarboxy acids having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the anhydrides or any other obvious equivalents. My preference, however, is to use polycarboxy acids having not over 8 carbon atoms.

The production of esters including acid esters (fractional esters) from polycarboxy acids and glycols or other hydroxylated compounds is well known. In the present instance the hydroxylated compounds obtained as described in Part 1, preceding, contain nitrogen atoms which may or may not be basic. Thus, it is probable particularly where there is a basic nitrogen atom present that salts may be formed but in any event under conditions described the salt is converted into an ester. This is comparable to similar reactions involving the esterification of triethanolamine; Possibly the addition of an acid such as hydrochloric acid if employed for elimination of the basic catalyst also combines with the basic nitrogen present to form a salt. In any event, however, such procedure does not affect conventional esterification procedure as described here- 1n.

Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purpose of economy it is customary touse either the acid or the anhydride. A conventional procedure is em ployed. On a laboratory scale one can employ a resin pot of the kind described in U. S. Patent No. 2,499,370, dated March 7, 1950, to De Groote and Keiser, and particularly with one more opening to permit the use of a porous spreader if hydrochloric acid gas is to be used as a catalyst. Such device or absorption spreader consists of minute Alundum thimbles which are connected toa glass tube. One can add a sulfonic acid such as paratoluene sulfonic acid as a catalyst. There is some objection to this because in some instances.

there is some evidence that this acid catalyst tends to decompose or rearrange the oxypropylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of collic acid, which is strongly acidic there is no need to add any catalyst. The use of hydrochloric acid gas has one advantage over paratoluene sulfonic acid and that is that at the end of the reactionit can be removed by flushing out with nitrogen, whereas there is no reasonably convenient means available of removing the paratoluene sulfonic acid or other sulfonic acid employed. If hydrochloric acid is employed one need only pass the gasthrough at an exceedingly slow rate so as to keep the polycarboxy acids such as diglyreaction mass acidic.

f4 Only a trace of acid need be: present; Il'have employed hydrochloric acid gas or the aqueous.

Water can be separated in a phase-separating trap. As soon asthe product is substantially free from water the distillation steps. This preliminary step can. be

event the neutral or slightly acidic solution ofthe oxypropylated derivatives described in Part 1 is then diluted further with suificient xylene, solvent, or the like, so that one has obtained approximately a 45% solution.

To this solution there is added a polycarboxylated reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglycollic acid, etc. The mixture is refluxed until esterification is complete as indicated by elimination of water or drop in carboxyl value. Needless to say, if one produces a half-ester from an anhydride such as phthalic anhydride, no. Water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional and have been so thoroughly described in the literature that further consideration will be limited to a few examples and a comprehensive ta- Other procedures for eliminating the basic residual catalyst, if any, can be employed. For example, the oxyalkylation can be conducted in absence of a solvent or the solvent removed after oxypropylation. Such oxypropylation end product can then be acidified with just enough con.- centrated hydrochloric acid or just neutralize the residual basic catalyst. To this product one can then add a small amount of anhydrous sodium sulfate (sufiicient in quantity to take up any water that is present) and then subject the mass to centrifugal force so as to eliminate the sodium sulfate and probably the sodium chloride formed. The clear somewhat viscous dark-amber liquid so obtained may contain a small amount of sodium sulfate or sodium chloride but, in any event, is perfectly acceptable for esterification in the manner described.

It is to be pointed out that the products here described are not polyesters in the sense that there is a plurality of both polyamino radicals and acid radicals; the product is characterized by having only one polyamino radical.

In some instances and, in fact, in many instances I have found that in spite of the dehydration methods employed above that a mere trace of water still comes through and that this mere trace of water certainly interferes with the acetyl or hydroxyl value determination, at least when a number of conventional procedures are used and may retard esterification, particularly where there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred. to use the following procedure: I have employed. about 2 Q0 grams of the polyhyconsiderably in excess of what droxylated compound as described in Part 1, preceding; I have added about 60 grams of benzene, and then refluxed this mixture in the glass resin pot using a phase-separating trap until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily this refluxing temperature is apt to be in the neighborhood of 130 to possibly 150 C. When all this water or moisture has been removed I also withdraw approximately grams or a little less benzene and then add the required amount of the carboxy reactant and also about 150 grams of a high boiling aromatic petroleum solvent. These solvents are sold by various oil refineries and, as far as solvent effect act as if they were almost completely aromatic in character. Typical distillation data in the particular type I have employed and found very satisfactory is the following:

I. B. P., 142 C. 1111., 242 C. 5 1111., 200 C. ml., 244 C. 10 1111., 209 C. ml, 248 C. 15 1111., 215 C. ml., 252 C. 20 ml, 216 C. ml., 252 C. 25 ml., 220 C. ml., 260 C. 30 1111., 225 C. ml., 264 C. 35 1111., 230 C. 1111., 270 C. 40 1111., 234 C. ml., 280 C. 45 ml., 237 C. 1111., 307 C.

After this material is added, refluxing is continued and, of course, is at a higher temperature, to wit, about to C. If the carboxy reactant is an anhydride needless to say no water of reaction appears; if the carboxy reactant is an acid, water of reaction should appear and should be eliminated at the above reaction temperature. If it is not eliminated I simply separate out another 10 or 20 cc. of benzene by means of the phase-separating trap and thus raise the temperature to or C., or even to 200 C., if need be. My preference is not to go above 200 C.

The use of such solvent is extremely satisfactory provided one does not attempt to remove the solvent subsequently except by vacuum distillation and provided there is no objection to a when these materials little residue. Actually,

99?. s aaeaeaaaaaam vwwwp.

are used for a purpose such as demulsification the solvent might just as well be allowed to remain. If the solvent is to be removed by distillation, and particularly vacuum distillation, then the high boiling aromatic petroleum solvent might well be replaced by some more expensive solvent, such as decalin or an alkylated decalin which has a rather definite or close range boiling point. The removal of the solvent, of course, is purely a conventional procedure and requires no elaboration.

In a number of examples instead of using solvent #'7-3 I found it more convenient to use xylene, one reason being the Xylene could be removed readily for examination of the solvent-free material. Reference is made to Examples 7b through 297). In these instances solvent #7-3 could be used instead of xylene, or a mixture of the two could have been used. This is the case particularly where the oxypropylated derivative showed decreased water-solubility. However, where the product showed significant watersolubility the difficulty arose that at the end of the esterification reaction the solvent and resultant or reaction mass was not homogeneous. Thus, in Examples 17) through 30 two-thirds of the solvent was xylene and one-third was methanol. These solvent proportions could be varied without objection within resonable limits. Twothirds of the indicated amount of solvent was indicated as xylene and after all the water was removed the nonhomogeneous mixture was rendered homogeneous by the addition of methanol equal to 50% of the original xylene. These solvent properties could be varied somewhat without change, the object being merely to eliminate water in presence of water-insoluble solvents and then add suitable semi-polar compounds to give a homogeneous solution.

Another obvious procedure, of course, is merely to distill off a solvent such as xylene or solvent #7-3 and then dissolve the product in a semipolar solvent, such as methanol, ethanol, propanol, etc. It is purely a matter of convenience to first employ a non-polar solvent (water-insoluble) to eliminate the water during distillation and then add a suitable polar solvent (hydrophile) to give a single-phase system.

TABLE 2 Amt. oi

Mol Wt Actual Poly- Besed on Hydroxyl carboxy Value g Cmpd Rcactani' (grs.

199 564 92. 6 199 564 87.0 199 564 08. 5 199 102. 0 199 78.0 199 120. 5 4 167. 5 82. 0 4 167. 5 76. 6 4 107. 5 57. 1 4 167. 5 S7. 6 4 167. 5 nhyd 08. 5 4 167. 5 Aconitic Acid 103.6 9 92. 6 1, 210 Diglycolic Acid 45. 8 9 92. 6 1, 210 Aconitic Acid 59. 5 9 92. 6 1, 210 Oxalic Acl 43. 0 9 92. c 1, 210 33. 0 9 92. 6 1, 210 38. 2 9 92. 6 l, 210 49. 6 3 73. 4 1, 530 36. 0 3 73. 4 l, 530 46. 6 3 73. 4 1, 530 A 33. 8 3 73. 4 1, 530 27. 0 3 73. 4 1, 530 Citraconic Anhy 30.0 3 73. 4 1, 530 Phthalic Anhyd... 39. 4 3 73. 4 1, 530 Diglycolic Acid 27. 5 3 73. 4 Oxaiic Acid 25. 8 3 73. 4 Maieic Anhyd 20. 1 3 73. 4 Phthalic Anhyd 30. 1 3 73. 4 Aconitic Acid 35. B

an appropriately reduced ratio of carboxylic'reactant.

Even the determination of the hydroxyl value by conventional procedure leaves much to be desired due either to the cogeneric materials previdark amber in color, and show moderate viscosity.

They can be bleached with bleaching clays, filtering chars, and the like. However, for the purpose of demulsification or the like color is not a factor and decolorization is not justified.

In the above instance I have permitted the solvents to remain present in the final reaction mass. In other instances I have followed the same procedure using decalin or a mixture of The procedure for manufacturing the esters somewhat more Vlscous' has been mustm It is unnecessary to point out, of course, that ted by precedmg examples If what has been said herein is the same regardless derivative and use a stoichiometrically equivalent PART 3 In the hereto appended claims the demulsifying agent is described as an ester obtained from a polyhydroxylated material prepared from a diamine. If one were concerned with a monohydroxylated material or a dihydroxylated mamore difliculty is involved in obtaining complete esterificafionl ondary alcoholic radical and a primary alcohol Even under the most carefully controlled conmdmal' Obvwusly than polypropylene glycols d' ions of oxypropylation involving comparatively could be obtained at le-ast theoretlcauy m Whlch are formed certain compounds whose compositions are still obscure. Such side reaction products can contribute a substantial proportion of the final cogeneric reaction mixture. Various alcohol group, etherization being involved, 01 course, in each instance. Needless to say, the same situation applies when one has oxypropylated polyhydric materials having 4 or more hydroxyls, or the obvious equivalent.

Usually no effort is made to differentiate between oxypropylation taking place, for example, at the primary alcohol radical or the secondary alcohol radical. Actually, when such products are obtained, such as a high molal polypropylene herein described one does not obtain a single boxylated reactant for the reason that apparently derivative Such as Homo) or (B0) in under conditions of reaction less reactive hywhich n has one and only one value for instance droxyl radicals are present than indicated by the 15 or or the like- Rather one obtains a hydroxyl value. Under such circumstances there cogenelic mixture of closely related touching is simply a residue of the carboxylic reactant homOlOglleS- These materials invariably have which can be removed by filtration or, if desired, high molecular weights and cannot be separated the esterification procedure can be repeated using from one another by any known procedure withto the: cop ending 'applicationrof pleteness of .This maybe. illustrated asiiollows vAssume-that 75 iage'zemrs -outidecomposition. rlhemropertieszotqsuchzmix- 'actantrone cannot draw :arsingleiormula-and 1 say that by .following suchyprocedure acne can readily obtain 80 .7011190 or 1100 of-suchzcompound. However,:in .the-:case of at leastrmonohydric'initialsreactants: one canlreadilyi drawthe formulasm'f a-large number oficompounds' which =appear:-in:-some oithe probable:mixturesoncan be prepared-as components" and-.mix ures which :are manufacturedconventionally.

': Simply by way of illustrationzreferencea ismade and PettingilLxSerialNo. -109;'7-91 ,1 filed'August :11, 1949 '(now Patent 2 5493434, granted April 3117, 1951).

'However, momentarily referring again .to :a monohydricone selects any such ssimple hydroxylated compound and subj ects-suchcompound to. ,oxyalkylation, such as oxyethylations, 1,01'YOXYP1ODY13UOI1,

-it becomes obvious thatone is really producing a "polymer of the terminal-group. the amount of oxide added is comparatively large,

.alkylene ox-ides except ;for athe This is particularly true awhere for-instance, l0,"20,30,40, 012-50 .llIlltS. .Ii'vsuch compound is subjectedto.oxyethylation so as to introduce units of ethylene oxide, it is well known that one does 1 not 'obtain 'ra ssinglerconstituent whichpfor'theFsaketof'zconvenienceimay 'beindicated'as RO(.C2H40)30OH. .Instea'd, one

obtains a *cogeneric mixture of zclosely "related homologues, :in' which the formula may bershown "as the following, 1R0 (C2H4O)-.hI-I, wherein rn, was far. as the statistical'average goesyis :,30, ;b,ut .the individual'members present insignificant-amount may varyffromiinstances where'n has a-value:of

25, andfperhaps'lessito-apoint where n mayrrepresent -or more. isuch 'mixturecis, aasz'stated, a cogeneric .closely':related series of touching vhomologous compounds. :Considerableinvestigation has been "made in 'regard 5130 sthe cdistribution curves for. linear polymers. Attention is cdirected to the article. entitled FundamentalaPrinciplesto f Condensation :Polymerization, ZbyirElory, which appeared in CherhicalrReviewarvOlume 39,':No. :l,

page .137.

Unfortunatelygaszhas'beenzpointedcoutzby Flory i and :other investigators, .therez is: no satisfactory method,'ibased. on either: experimental; or .:mathe- "matical examination, of:indicatingitheiexactzpro- .portion of the various members rofitouchingchomologous series which appear in :cogeneric z'condensation products-*of' the kind described. "This means that from the practical =staridpoint,'- i. e., the-ability to'described'how to make ithe product under considerationan'dhow'to repeatsuch production time after time'without 'difficultyyitds necessary-to resort to some other method-of description, orelseconsider the value of n, in formulas such as thosewhich'have appeared :previ- :ously and which-appear -in the claims, I as repre- .senting both individual .oonstituents?intwhich' n Y has a single definite -.value,

and also with theunderstanding that .n represents the average :statistical value based ,on the assumption .of I comreaction.

DeIGroote, Wirtel 1 .rkeroseneesoluble .an'd watereinsoluble.

:markably enough, .in many in any particular :example the molal rate of propylene oxide per hydroxyl-is15-to'l. In-a genericiormulaldtol could be 10, 20 :or some other amount and indicated by n. Referringlto this specific "case actually one obtains products in which it probably varies from 10 to 20, perhaps even further. "The average value,'however, is 15, assuming, as previously stated, that the reaction viscmnplete. .The product described-by theformula'is best described also in terms of method of manufacture.

The significant fact in regard to the oxypropylated polyamines herein .describedis .that in the initial stage they are substantially vzall water-soluble, for instance, up to a melocular weight of 1,500 or thereabouts. Actually,such molecular weight represents .a. of some higher molecular weight materials and some lowor molecular weight materials. The-higher ones are probably .water-nsoluble. The: product'may tendto emulsify or sdisperse somewhatibecause some of theconstituents, being a cogenericniix- ,ture, are water-soluble but the vbulkareinsoluble. Thus onegetsemulsifiability or dispersibility as noted. Such products are invariably xylene-soluble regardless of whether-the original reactants were or not. Reference is made to .what .has been said previously in ..regard to retical molecular weight gets somewhere past 4,000 .or at approximately 5,000 theiproductis 'LThese Zkeroseneesoluble oxyalkylationpro'ducts are most desirable .for ,preparingthe .esters. TIT have .prepared .hydroxylate'd compounds not only .up .to the theoretical molecular weightshownprevious- 1y, .i. e., aobut .6,'000'but.also some .which were .muchhigher. .I have.preparedlthem, not .only from .propylenediamme,-but also .irom. .oxyeth:;zl ated .or oxybutylated .fderivatives previously .referred to. The-exactcomposition is open/sequestionior reasons which are common to all.oxyalkylation. .It .is interesting to note, however, that .the. molecular weights based on hydroxyl determinationsat this point wereconsiderably. less, inthe neighborhood .of .a thirdor a fourth .of -.the value at maximum point. Referring .again .to previousdata it..is to.be noted, however, thatover the .range .shown of .-kerosene-.solubility .the hy- ..dr0xyl molecular. weightlhas. invariably stayed at two-thirds or ,five-eighths .of the theoretical molecular weight.

.It becomes obvious when carboxylic esters are prepared from such .hignmolecular weight-.materials that the ultimate esterificationproduct again .must be acogeneric mixture. Likewiseit is obvious that the contribution to the total molecular weight. made by the polycarboxy acid is small. By thesame token one=wou1dvexpectthe effectiveness of the .demulsifler .to :be comparable to the ,unesterified .hydroxylated material. 2R3 instances'therproduct is distinctly better.

PART 4 As pointed out previously the final-productobtained is a fractional ester having free carboxyl radicals. Such product can .be used-asan intermediate for conversion into other derivatives which are effective for various purposes, suchas the breaking of petroleum emulsions of the kind hereindescribed. .For instance, such product-can .be neutralized with .an amine '50 as to increase its-.water-solubility such as .triethanolamine, tripropanolamine, oxyethylated .triethanolamine low molal alcohols, methyl, ethyl, propyl, butyl, etc., and also high molal alcohols, such as octyl, decyl, cyclohexanol, benzyl alcohol, octadecyl alcohol, etc. Such products are also valuable for a variety of purposes due to their modified solubility. This is particularly true where surfaceactive materials are of value and especially in demulsification of water-in-oil emulsions.

Having thus described my invention, what I claim as new and desire to obtain by Letters Patent, is:

1. A hydrophile synthetic product which is from the group consisting of carbon, hydrogen, oxygen and nitrogen; (b) the monomeric diamino compound have a molecular weight of not over 800 and at least a plurality of reactive diamino compound be within the range of '7 to 70; (e) the monomeric diamino compound represent not more than 20% by weight of the oxycarboxy and tricarboxy acids composed of carbon, hydrogen and oxygen and having not more than 8 carbon atoms.

2. A product as in claim 1 in which at least one of the nitrogen atoms of the oxypropylated monomeric diamino compound is basic.

3. A product as in claim 1 in which both nitrogen atoms of the oxypropylated monomeric diamino compound are basic.

4. A product as in claim 3 in which the polycarboxy acid is a dicarboxy acid.

5. product as in claim 4 in which the mon- 6. The product of claim 1 wherein the dicarboxy acid is diglycollic acid.

7. The product of claim 1 wherein the dicarboxy acid is maleic aci 8. The product of claim 1 wherein the dicarboxy acid is phthalic acid.

9. The product of claim 1 wherein the dicarboxy acid is citraconic acid.

10. The product of claim 1 wherein the dicarboxy acid is succinic acid.

No references cited. 

1. A HYDROPHILE SYNTHETIC PRODUCT WHICH IS THE ESTER OF (A) A POLYCARBOXY ACID WITH (B) HIGH MOLAL OXYPROPYLATED MONOMERIC DIAMINO COMPOUND WITH THE PROVISO THAT (A) THE MONOMERIC DIAMINO COMPOUND BE FREE FROM ANY RADICAL HAVING AT LEAST 8 UNINTERRUTPED CARBON ATOMS AND BE COMPOSED OF ELEMENTS SELECTED FROM THE GROUP CONSISTING OF CARBON, HYDROGEN, OXYGEN AND NITROGEN; (B) THE MONOMERIC DIAMINO COMPOUND HAVE A MOLECULAR WEIGHT OF NOT OVER 800 AND AT LEAST A PLURALITY OF REACTIVE HYDROGEN ATOMS; (C) THE OXYPROPYLATED MONOMERIC DIAMINO COMPOUND HAVE A MOLECULAR WEIGHT OF 2000 TO 30,000 ON AN AVERAGE STATISTICAL BASIS; (D) THE RATIO OF PROPYLENE OXIDE PER INITIAL REACTIVE HYDROGEN ATOM OF THE MONOMERIC DIAMINO COMPOUND BE WITHIN THE RANGE OF 7 TO 70; (E) THE MONOMERIC DIAMINO COMPOUND ON A RESENT NOT MORE THAN 20% BY WEIGHT OF THE OXYPROPYLATED MONOMERIC DIAMINO COMPOUND ON A STATISTICAL BASIS; (F) THE PRECEDING PROVISOS BEING BASED ON THE ASSUMPTION OF COMPLETE REACTION BETWEEN THE PROPYLENE OXIDE AND THE MONOMERIC DIAMINO COMPOUND; (G) THE NITROGEN ATOMS ARE LINKED BY A PROPYLENE RADICAL; (H) THE RATIO OF POLYCAROBXY ACID TO OXYPROPYLATED MONOMERIC DIAMINO COMPOUND BEING ONE MOLE OF THE FORMER FOR EACH REACTIVE HYDROGEN ATOM OF THE LATTER; AND (I) THE POLYCARBOXY ACID BE SELECTED FROM THE GROUP CONSISTING OF ACYCLIC AND ISOCYCLIC DICARBOXY AND TRICARBOXY ACIDS COMPOSED OF CARBON, HYDROGEN AND OXYGEN AND HAVING NOT MORE THAN 8 CARBON ATOMS. 